Numerical impedance relay misoperation 2

[bettoni]

Hello All,

Recently I´ve experienced a problem with a 7SA513 Siemens protection relay. Here´s the story.

I took it from our stock to install in a substation and when we tried to turn it on we found that the relay didn´t perform the complete starting process. It took us like 3 hours to get a complete initialization process, in wich the relay does its self-tests. Then it turned on ok but when we tried to download the new settings the relay got blocked.

I´m worried if the unit can get damaged in large stock times. Also I don´t know if there are some recommended practices to put this tipe of equipment in warehouses. Here we only use an air conditioned room. The relay I´m talking about is three years old and it have never been installed since we bought it. We chose another 7SA513 and did the same behaviour (and it even never started).

Please tell me if someone had experienced this, and if this kind of behaviour means that the equipment is no more available to use.

I already sent to the manufacturer this doubt and I´m waiting the answer.

 

[alehman]

It is possible there is a backup battery for memory retention that may have run down while in storge. You would need to consult the user manual to find out.

 

[arnabanindita]

Please refer to page number 325 of 7SA513 V3 manual where storage criterian is writen.
I am mentioning some salient points:
It is recommended to reduce storage temperature to the range +10 deg cent to +35 deg cent this prevents from early aging of electrolytic capacitors which are contained in the power supply.
For very long storage periods, it is recommended that the relay should be connected to the auxiliary voltage source for one or two days every other year, in order to regenerate the electrolytic capacitor....